Zamioculcas plant named &#39;Dowon&#39;

ABSTRACT

A new variety of  Zamioculcas  plant named ‘Dowon’ that is characterized by an erect vase-shaped habit, and stiffly-held compound, glossy leaves which emerge mid-green maturing to black, is described.

Genus and species: Zamioculcas zamiifolia.

Variety denomination: ‘Dowon’.

CROSS-REFERENCE TO RELATED APPLICATIONS

A Community Plant Variety Rights application was filed with theCommunity Plant Variety Office of Feb. 16, 2015, File Number 2015/0379;and Plant Breeders Rights were granted for this variety with theDepartment of Plant Variety Protection—Korea Forest Service on Dec. 26,2013, Registration Number 4721. This variety has not been made publiclyavailable or sold more than one year prior to the filing date of thepresent application.

BACKGROUND OF THE NEW PLANT

The present variety relates to a new and distinct variety of Zamioculcascommonly known as Aroid Palm or ZZ Plant. The new variety is knownbotanically as Zamioculcas zamiifolia and will be referred tohereinafter by the name ‘Dowon’.

Zamioculcas is a succulent plant with dark green glossy compound leaveswhich stores water in its thick petioles. Zamioculcas is native totropical and sub-tropical east and southeast Africa and only onespecies, zamiifolia, is known. Zamioculcas is grown and used as atropical or indoor foliage plant.

Zamioculcas plants grow from an underground tuber which also comprisesthe stem. All of the growth above ground consists of erect or semi-erectlarge pinnately compound leaves borne on stiff petioles. Each leafletwithin the compound leaf is attached to a central rachis. The attachmentis typically sessile or minutely petiolulate.

The new Zamioculcas variety named ‘Dowon’ was discovered in 2006 by theinventor at the inventor's nursery in Segok-dong, Seoul, South Korea.The inventor observed that a single plant of typically green-foliagedZamioculcas had produced on one of its compound leaves a set of leafletswith uncharacteristically very dark green coloration, tending to darkenfurther as the leaflets expanded. When fully expanded, the leaflets,rachis and petiole became entirely black or near-black. Zamioculcas maybe propagated from individual leaflet cuttings. The inventor continuedto observe the original plant for many months before carrying out thefirst asexual propagation in 2006 using black leaflets. The inventor wasinterested to know if the black leaflets would root and would producenew plants with the same characteristic of leaf blackening. The inventorobserved that new foliage growth from the rooted black leaflets firstemerged typically green in color but became black or nearly black as thecompound leaf expanded and matured.

The inventor has repeated this process of reproduction from black leavesand has determined that the development of black plants as hereindescribed is consistent. The inventor has determined that ‘Dowon’reproduces true to type in successive generations of asexualreproduction via leaflet cuttings.

SUMMARY

The following traits have been repeatedly observed and represent thedistinguishing characteristics of the new Zamioculcas variety named‘Dowon’. In combination these traits set ‘Dowon’ apart from its speciesand from all other varieties of Zamioculcas known to the inventor.‘Dowon’ has not been tested under all possible conditions and phenotypicdifferences may be observed with variations in environmental, climaticand cultural conditions, however, without any variance in genotype:

1. Plants of ‘Dowon’ are erect and vase-shaped, consisting of stifflyheld compound leaves.

2. The leaflets of the compound leaves of ‘Dowon’ are bornepredominantly in opposite pairs. Some leaf pairs are sub-opposite orclosely alternate.

3. The leaflets of ‘Dowon’ are very closely attached, either sessile orminutely petiolulate, to a central rachis.

4. The first emerging foliage growth of ‘Dowon’ is bright glossymid-green in color.

5. As each new compound leaf ages over a period of 1 to 2 months, thecolor of the leaf darkens through dark olive green, then developingstreaks or patches of very dark green tending to black, to eventuallyentirely black.

6. Mature compound leaves, including petioles, rachis and leaflets of‘Dowon’ are entirely black.

7. The leaf surfaces of ‘Dowon’ are glossy.

8. The inflorescence of ‘Dowon’ emerges at or just above ground leveland consists of a pale green spathe surrounding a cream-white spadix.

DESCRIPTION OF THE PHOTOGRAPHS

The accompanying color photographs illustrate the overall appearance of‘Dowon’showing the colors as true as it is reasonably possible to obtainin colored reproductions of this type. Colors in the photographs maydiffer from the color values cited in the detailed botanicaldescription, which more accurately describe the actual colors of the newvariety ‘Dowon’. Except for FIG. 9 which was taken in Miami, Fla., allphotographs have been made from plants which have been grown by theinventor at the inventor's nursery in Seoul, South Korea. No growthregulators have been applied to any of the plants in the drawings.

FIG. 1 shows a mature plant of ‘Dowon’ in all stages of foliage colordevelopment.

FIG. 2 shows a plant of ‘Dowon’ which is fully mature and is notproducing any new green foliage.

FIG. 3 depicts a close-up view of foliage of ‘Dowon’ as it begins todarken; the vein midribs are prominent at this stage.

FIG. 4 depicts a compound leaf of ‘Dowon’ which is in the mid-stage ofturning from green to black.

FIG. 5 depicts a compound leaf of ‘Dowon’ which has matured to entirelyblack in color.

FIG. 6 depicts a leaflet of ‘Dowon’ in its semi-mature (olive greencolor) condition.

FIG. 7 depicts a leaflet of ‘Dowon’ in its mature (black color)condition.

FIG. 8 depicts a fresh inflorescence (spathe and spadix) of ‘Dowon’ andan unfertilized aged inflorescence with strongly recurved peduncle,spathe and spadix.

FIG. 9 depicts a six months old plant of ‘Dowon” which has been grownout of doors in a 1-gallon container in Miami, Fla. and from which thedetailed botanical description has been made.

DESCRIPTION OF THE NEW VARIETY

The following is a detailed description of the new Zamioculcas plantnamed ‘Dowon’. Data was collected in Santa Barbara, Calif. usingsix-month-old plants which were grown from a rooted leaflet from Miami,Fla. The description of the inflorescence of ‘Dowon’ was prepared fromplants grown by the inventor in South Korea. The color determinationsare in accordance with the 2007 edition of The Royal HorticulturalSociety Colour Chart, London, England, except where general color termsof ordinary dictionary significance are used. The growing requirementsare similar to other Zamioculcas.

-   Botanical classification:    -   -   Genus.—Zamioculcas.        -   Species.—zamiifolia.        -   Denomination.—‘Dowon’.        -   Common name.—Aroid Palm.-   Parentage: Sport from Zamioculcas zamiifolia (species, unpatented).-   Plant:    -   -   Plant height.—30.0 cm.        -   Plant width.—22.0 cm in width.        -   Roots description.—Fleshy; coarsely lateral branching; 1.0            mm to 3.0 mm in diameter; very fine root hairs; root color            is 158A.        -   Root development.—At soil temperatures 20° C. to 25° C.,            root initials are evident within 3 days; roots will reach            the edge of a 1-gallon container in 21 days.        -   Time to develop roots.—14 days at air and soil temperature            of 25° C.        -   Propagation type.—Asexual reproduction is accomplished by            leaflet cuttings.        -   Plant vigor.—Vigorous; prolific production of new leaves            emerging from underground stem; 6 to 8 compound leaves per            plant.        -   Plant growth rate.—A 1-gallon container plant may be            produced in 12 to 16 weeks from a 4.0-cm cell transplant, or            in 5 to 6 months from insertion of a leaflet cutting.        -   Plant growth habit and shape.—Upright and vase-shaped.        -   Plant hardiness.—None; ‘Dowon’ does not tolerate freezing            conditions.        -   Cultural requirements.—‘Dowon’ thrives in high temperatures            (above 70° F.), in full-sun or partial-shade.        -   Use.—Interior decorative landscaping; outdoor landscaping in            regions with no frost.-   Tuber (underground stem):    -   -   Shape and dimensions.—Short cylindrical; 5.0 cm in length,            2.0 cm to 3.0 cm in diameter.        -   Surface texture.—Rough with root initials and leaf initials.        -   Color.—Ranges between 158A and 165D.-   Foliage (compound leaves):    -   -   Quantity per plant.—6 to 8 compound leaves arise from            underground stem.        -   Petiole dimensions and shape.—Up to 10.0 cm in length; shape            is cylindrical; diameter tapers from 10.0 mm at emergence            from surface to 6.0 mm below lowest leaflet.        -   Petiole surface and color.—Smooth, glabrous, strong and            stiff; color is 152D (new green growth) and 202A (mature,            black growth).        -   Rachis dimensions.—Up to 15.0 cm in overall length with            internode distance varying from 6.0 mm (between            near-opposite leaflets) to 35.0 mm between leaflets furthest            apart.        -   Rachis surface and color.—Smooth, glabrous, strong and            stiff; color is 152D (new green growth) and 202A (mature,            black growth).-   Foliage (leaflets):    -   -   Attachment.—Sessile or minutely petiolulate.        -   Dimensions (largest).—9.0 cm in length and 4.7 cm in width.        -   Aspect.—Erect, held between 30° and 45° away from the            rachis.        -   Shape.—Obovate — elliptic.        -   Apex.—Acuminate, point extends 1.5 mm.        -   Base.—Cuneate — rounded, occasionally oblique.        -   Surface.—Glossy (both surfaces).        -   Color (both surfaces).—New green growth: 144A. Semi-mature            growth: Mottled 139A against 146A. Mature black growth:            203B.        -   Venation.—Pinnate, not prominent; appears as shallow            depressions on adaxial surfaces and shallow ridges on            abaxial surfaces).        -   Vein color (new green growth, both surfaces).13 144A or very            slightly lighter.        -   Vein color (semi-mature growth, adaxial surface).—Midrib is            187A; elsewhere is 146A or slightly lighter.        -   Vein color (semi-mature growth, abaxial surface).—Ranges            between 139A and 146A.        -   Vein color (mature growth, both surfaces).—203B. Petiolules            (where present): Dimensions: Length is 1.0 mm to 3.0 mm and            diameter is 1.0 mm to 3.0 mm. Shape: Sulcate. Surface            texture: Smooth. Color: 144A (new green growth); 139A            (semi-mature growth); and 203B (mature black growth).-   Inflorescence:    -   -   General.—Spadix flowers not closely observed; pollination            has not been observed.        -   Spathe.—Appearance: Short cylindrical tube with longer ovate            blades, 5.0 cm to 6.0 cm in length and 4.0 cm to 5.0 cm in            width. Length: 1.5 cm. Diameter: 1.5 cm. Apex: Acuminate,            point extends up to 1.0 cm. Base: Sheathing. Spathe color            (both surfaces): Ranges between NN155C and 145C. With age:            Contracts with age.        -   Spadix.—Shape: Tapering cylindrical. Length: 6.0 cm.            Diameter: 1.5 cm at widest, narrowed to 1.0 cm at the base.            Color: NN155D. With age: Contracts with age.        -   Peduncle.—Appearance: Short and erect. Length: Approximately            2.0 cm. Diameter: 0.5 cm. Color: N189B. With age: Peduncle            extends and becomes strongly recurved, approximately 8.0 cm            in length, 0.5 cm in diameter, and color fades to N187B.-   Resistance or susceptibility to pests and diseases: ‘Dowon’ has been    observed to be less attractive to common pests which affect indoor    plants including mites (Tetranychidae), aphids (Aphididae) and    mealybugs (Pseudococcidae).

COMPARISON TO PARENTAL LINE

‘Dowon’ may be compared with its sport parent, the species Zamioculcaszamiifolia (species, unpatented). Whereas the compound leaves (includingleaflets, rachis and petiole) of Zamioculcas zamiifolia are green incolor, a mature plant of ‘Dowon’ is uniformly black or near-black. Inaddition, the inventor has observed that ‘Dowon’ is less attractive tocommon pests which affect indoor plants including mites, aphids andmealybugs.

‘Dowon’ may also be compared with the species Zamioculcas zamiifolia bythe rate of growth of new leaves arising from a rooted leaf cutting.Altogether, the inventor has observed that a mature (60.0 cm in height)fully-black plant of ‘Dowon’ may take 7 to 8 months to produce comparedwith 3 to 4 months for production of green Zamioculcas zamiifolia.

No commercial varieties of Zamioculcas which exhibit black foliage areknown to the inventor.

I claim:
 1. A new and distinct variety of Zamioculcas plant named‘Dowon’ as illustrated and described herein.